Sherlock and Rosie
by GhostWriter030791
Summary: Rosie knows her uncle Sherlock from the letters and gifts over the years; she knows his handwriting better than she knows her own. Unknown to her parents, they all have a point. AU: this assumes Sherlock went undercover after the end of Series 3, survived, and continued working undercover while Rosie was growing up with her parents. Mary is still alive in this.


A month after Rosie had been born, John got a postcard in the post. It had one word scrawled in Sherlock's messy print:

 _Congratulations._

John smiled sadly, walked back into the flat he shared with his wife and daughter and pinned the card to the bulletin board in the kitchen.

"John?" Mary called from behind him.

John smiled and turned towards his wife holding Rosie in her arms. "I love you."

Mary grinned. "I should hope so, husband."

John shook his head and took Rosie from her. "I love you too, Rosamund Elizabeth Sherlock Watson."

Mary glanced up at the postcard on the board and her smiled widened. "Uncle Sherlock loves you too, Rosie dear."

John cleared his throat and nodded, before following his wife into the kitchen.

* * *

On Rosie's fifth birthday, a package arrived at the Watson residence. Rosie watched, curiously, as her father signed for it and brought it in for Rosie.

"John?" Mary called out. "Who was at the door?"

John glanced at the package, noted the lack of sender address, and smiled slightly. "Delivery man. It's a package for Rosie."

Mary frowned. "For Rosie? Who'd be sending Rosie packages?"

John held out the small box, displaying the scrawled name of _Rosamund Watson_ in a familiar handwriting. Mary shook her head.

Rosie watched as her father opened the box carefully and pulled out a large book titled _Romanian Myths and Legends._ On the inside was written, " _To my dear Rosa. May you develop more of an imagination than your father. -S_ "

John laughed as he read the note and then handed the book to Rosie. She took it carefully and began flipping through the pages.

Later that night, just before bed, Rosie began reading the classic tales of Romania in halting sentences, helped along by her mother and father.

* * *

Two days before Rosie's tenth birthday, Rosie got off the bus after school and found on the doorstep a small box with her name on it. Recognizing the writing on the box, she picked it up and brought it into the house.

"Hello, love." Her mother said, working on her computer in the kitchen. She saw what was in her hands and nodded. "What's that?"

Rosie dropped her bag on the couch and brought it to her mother while she went to get some scissors to open the box. "It's from Uncle S. It's my birthday present."

Mary smiled. "Well, it's not your birthday yet."

Rosie turned to look at her mother with her mouth open. "But…it's from Uncle S."

Mary laughed. "Alright, alright."

Rosie took the box from her mother and carefully broke the tape on the box. Inside was a beautifully detailed and delicate Chinese puzzle box.

Rosie had been reading about puzzle boxes after her Christmas present last year when she'd gotten three books about puzzle boxes from Uncle Sherlock. She'd been fascinated with the concept and had been reading about them for the last six months.

Her mother looked over her shoulder. "Is that a puzzle box?"

Rosie grinned up at her mother and nodded, shaking the box gently. Something rattled inside it. "The box is not the gift," she said. "There's something inside.

Mary smiled and then nodded at the box. "Well, I think you'd better get on it, then."

It took her three days, mainly because both her parents insisted she spend time on her homework instead of spending all her time on the box. When it finally clicked open, she squeaked in delight.

Her father was home with her this time and glanced up from the paper he was reading. "Did you get it?" he asked.

Rosie nodded, and gently opened the box, pulling out a small jade dragon on the end of a long chain. She held it up for her father to see, and he smiled. "I hope that's not worth nine million pounds."

Rosie laughed. "Doubt it." Looking down she saw the note. " _Well done, my Rosa. Many happy returns. -Uncle S._ "

Rosie grinned and slipped the necklace around her neck. When she looked up, her father looked sad. "What's wrong?" she asked.

John shook his head. "Nothing." He looked at her intently for a moment. "You know your Uncle Sherlock loves you, right?"

Rosie nodded. "Of course."

John pinched his lips together for a moment before smiling sadly. "Come on, we can pick up your Mum and you can show her your new present."

Rosie grinned and ran upstairs to get her jacket. She glanced up at her bulletin board with the dozens of postcards she'd gotten over the years and shook her head. She straightened the picture of Sherlock and her parents at their wedding that sat on her desk and skipped out the room after her father.

* * *

When Rosie turned sixteen she was sitting at home, feet up on the coffee table as she tapped away at her computer. Her nails clicked against the keys as she worked on a paper for school, and she leaned back against the couch, staring up at the ceiling when Mycroft appeared in her vision.

Rosie yelped in surprise. Mycroft just chuckled. "You should be more observant, Rosamund."

Rosie rolled her eyes. "If you weren't a creeper who sneaks up on people…"

Hearing her yell, John and Mary rushed into the room and stopped when they saw Mycroft.

"Hello, Mycroft," John said civilly. "What do we owe the pleasure."

Mycroft ignored the icy tone from John and turned to Rosie. "I'm here on official business, John." He smiled gently. "I have a gift for Miss Rosamund."

Rosie put her computer down and stood up to face him. "A gift?"

Mycroft nodded. "I understand you are playing your violin for a charity group tomorrow. Hoping to raise money for the animal shelter."

Rosie nodded. "Yes. Me and a couple of others from school are doing it as part of our community service project…"

Mycroft put his hands on his umbrella and turned as Anthea came in with a sleek, black violin case. "Well, I think it's about time you had a proper violin, don't you?"

Rosie took the case from Anthea, and heard her father say, "That's not what I think it is, is it?"

Mycroft smiled at John. "He was very insistent."

Rosie opened the case and pulled out an older model violin, but in good condition. "This is a Strat." She whispered, running gentle fingers over the wood. She looked up at Mycroft with her mouth open. "I can't accept this."

Mycroft leaned on his umbrella. "I think you can, my dear." He reached into his pocket and pulled out a small notecard:

 _Rosa- Your instinct is going to be to refuse, but it is my understanding that you are an excellent player. It was a gift to me long ago, and beautiful instruments like this are meant to be played. Look after it for me; consider it a favor. Many happy returns. -Uncle S._

Rosie looked up at Mycroft and then back down at the violin, again smoothing gentle fingers against the smooth wood.

It was John that spoke up. "Why don't you show Mycroft what you are capable of, Rosie."

Rosie swallowed, and picked up the instrument, pulling the bow out with it. Underneath the violin was a pile of sheet music, the first on top titled " _Rosa's Waltz. Composed by: Sherlock Holmes._ ".

Rosie picked up the music, glanced at it for a moment, and then walked over to her music stand in the corner of the living room. After a moment, she took a deep breath, put the violin under her chin, adjusted her neck, and slowly began playing the music in front of her. She was so lost in the music that when she finished she had forgotten there were other people in the room with her. Looking up, she saw her parents watching with both pride and sadness.

Mycroft had gone.

She smiled slightly and then placed the violin carefully back in its case.

Two days later she played several of the compositions left to her in the case for the charity concert. The waltz written for her she kept for herself, in the same folder she kept her own compositions and the waltz her uncle had written for her parent's wedding.

Some things were too personal to share with the public. It was a thought she was certain her Uncle Sherlock, a man she had never met, would have agreed with wholeheartedly.

* * *

When Rosie was twenty-five she was studying folklore and literature in at a Paris University. She gotten a phone call from her parents that morning to wish her happy birthday, and she was curious to see if a package would show up sometime either in England or Paris. Sherlock had never missed a birthday or Christmas and would randomly send postcards whenever he felt the urge.

She'd never met him, but her uncle had always been a part of her life. She knew his handwriting better than she knew her own.

Rosie was sitting at a café in Paris working on a paper when a waiter came over and handed her a note. "Miss Watson?"

She glanced up. "Yes."

He handed her the note. "This was left for you at the front counter."

She frowned. "Left by who?"

The waiter shrugged. "I don't know. The closers found it last night with instructions to give it to the young woman sitting at this table at eight o'clock this morning."

Rosie frowned harder. "Really?" she had only made the decision to get breakfast there that morning because she'd been sick the last week and hadn't had the opportunity to go shopping. It was impossible for anyone to know almost twelve hours before that she would decide to get breakfast at this particular café at that particular table.

Thinking about it for a moment, the light bulb came on. "Ah." There was only one person who would have been able to figure that out.

Taking the note from the waiter, Rosie opened the envelope and pulled out a crisp, white notecard. Printed on it in neat, typed letters were the words: " _Louvre. 7:00 tonight."_

Rosie frowned at it, expecting to see her uncle's messy scrawl. It was odd to not get a handwritten note.

Pinching her lips and staring at the note, she flipped it over and didn't see anything.

The alarm on her phone beeped at her, indicating she was going to be late for class if she didn't hurry, Rosie slipped the note into her book as a bookmark and headed towards the university.

At a quarter to six that evening, Rosie glanced up at the clock and shut the book she'd been working on. She tapped her fingers on the note thoughtfully. Her instincts told her something was off, but at the same time she only ever got mysterious notes from one person, and she'd always known he was no danger to her.

She took a deep breath, noted the time, and reached out to grab her cardigan. As she left her flat, she flagged down a cab to take her to the museum.

Rosie arrived at the museum two minutes to seven, and stood outside the entrance, curious as to what she was supposed to be looking for. At that time of night there were only a few people milling about, and she shivered in the cool, autumn air. At seven o'clock her phone beeped, indicating a text message, and she reached into her bag to get it.

The needle in her neck was shocking, and she immediately lashed out with a muffled cry as a hand clamped down on her mouth. Darkness immediately washed over her vision, and although she continued to struggle, she knew it was a fight she wasn't going to win.

* * *

An undetermined time later Rosie jerked upright, gasping for air. Her tongue was thick and heavy and felt stuck to the roof of her mouth. She groaned, head pounding, and she leaned against the thick cement walls, blinking away the stickiness in her eyes that told her she'd been unconscious for at least a few hours with her contacts in.

"You're awake." A man's voice with a French accent said. Rosie jerked in surprise and glanced around the room. Sitting across from her, in a metal chair found at outside events, an older man in jeans and a tee shirt sat with his arms crossed, staring at her.

"Who are you?" Rosie croaked out. "What do you want from me?"

The man shrugged. "You? Nothing. You're just bait."

Rosie blinked at him, brushing blonde hair out of her face as she did so. "Sorry? Bait?"

The man hummed at her. "Yes. Your godfather has something of mine and I'd like it returned."

Rosie shook her head. "My godfather…Sherlock?" at the man's nod, she sighed and leaned against the wall. "Listen, Sherlock is dead. He's been dead for, gosh, twenty-five years?" that was the story her father had said to tell anyone who might come asking for Sherlock. "So I'm bait for a dead man?"

The man smiled. "Oh, he's a dead man all right. But you and I both know he's currently alive and running around somewhere."

Rosie glared at him and moved to stand when she noticed the metal cuff around her ankle tied to a short chain against the wall. She frowned.

"Your godfather doesn't have many weaknesses, Miss Watson." The man said. "Not many that he would be willing to negotiate with anyway. But your family, and in particular his darling goddaughter, are perhaps the only thing that can get him to come out and play."

Rosie said nothing, just crossed her arms and leaned against the wall, frowning. The man smiled at her. "Don't worry. I'm not interested in hurting little girls. Especially ones who haven't done anything to me. If your godfather pulls through, and I expect he will, you can go home, unharmed."

Rosie licked her lips. "And if he doesn't?"

The man got up and shrugged. "Well, that would be unfortunate, wouldn't it."

* * *

Rosie sat shivering in the cool air of what she had finally determined to a cellar of some kind. She had wrapped her cardigan tighter around herself and was fiddling with the jade dragon necklace Sherlock had given her years ago.

She sighed and leaned her head against the wall, before glancing down at her ankle and the metal cuff that was tight around her ankle.

"Sod this," she finally whispered to herself. Struggling over to her ankle, she twisted the dragon necklace and unsheathed the small pin inside it. Reaching down she began to fiddle with the lock, trying to remember what she'd learned from her lock picking books she'd gotten as a Christmas present from Sherlock when she was a child.

The lock finally clicked open with a loud snap, and Rosie uncuffed herself. Standing up she slid the pointed end of the pin between her fingers, and the bottom half of the necklace into her pocket. Quickly turning her rings upside down on her right hand, she moved toward the doorway.

Putting her ear against the door, Rosie could hear the sounds of a struggle on the other side, and had just moved away from the door when it slammed open. The man from before stumbled inside, bleeding from a split lip.

He snarled at her and advanced towards her. Rosie let him get within arms reach before reaching out with the pin and slashing at his eyes. He jerked backward, and then reached for her again and she slapped her hand down hard with her right hand, sharp points of her rings digging large gashes into his arm. As he howled in pain, Rosie took the pin and slammed it into his shoulder, causing him to fall to the ground.

Rosie skipped around him and was almost to the door when he reached out and grabbed her ankle. She fell forward hard, hitting her head on the edge of the door. Blood streamed into her eyes, and she kicked with her ankle while trying to wipe the blood from her vision.

The man dragged her to him and punched her, hard, across her right cheek. Her vision wavered and she felt herself collapse on the ground. She reached out with the pin again, and slashed out blindly, feeling it make contact with something and hearing a cry of pain from the man attacking her.

She kicked out again and heard something crunch under her foot before she struggled to her feet and made for the door again, vision blurred and head aching. Once more, something caught her ankle and she went down again, feeling something snap in her hand as she fell forward again.

Rosie curled in on herself in pain, bracing herself for an attack when there was the sound of a man's angry roar and the hand gripping her ankle was suddenly gone.

A few moments later, gentle hands gripped her shoulders and began helping her to her feet. It took her a moment before her brain managed to catch up with the words being spoken to her.

"Rosa. Rosa! Rosa answer me, damn it"

Rosie blinked as she tried to focus on the face in front of her.

Staring at her, eyes full of concern, was a tall, thin man with dark hair streaked with gray and blue eyes. He quickly shrugged out of his large blue jacket and wrapped it around her gently. He quickly took his scarf off and began dabbing at the cut on her head.

She blinked again, trying to formulate words. "Uncle Sherlock?"

He smiled gently at her. "Hello, Rosa."

Rosa sighed and leaned her head against his shoulder, taking deep breaths. It was then she let the darkness swallow her up.

* * *

When Rosie opened her eyes again, she could see the stark white walls of a hospital and the rhythmic beeping of a heart monitor. She groaned, and rolled her head to see her mother asleep in the chair beside her.

"Mum…" she whispered.

Mary opened her eyes quickly. "Oh, you're awake. How're you feeling?"

Rosie glared up at her, and her mother laughed. "Oh, you're fine."

"Where's Uncle Sherlock?"

Her mother's lips twitched. "He's in the hallway with your father. I think they're having a domestic."

Rosie rolled her eyes and then had to resist the urge to vomit at the sensation. "Did they pick up my necklace? I left it in the cellar."

Her mother nodded. "Yeah. They pulled it out of a man's hand."

Rosie blinked and looked down at the cast on her wrist. "What's wrong with me?"

"Besides a lot?" Mary asked with a smirk. At her daughter's look, she smiled. "Minor concussion, black eye, and a fractured wrist. You should be able to go home in a day or so."

Rosie glanced over at her mother. "They didn't want to hurt me. They just wanted…"

"Me." A strong male voice said from the doorway. When Rosie and Mary turned to look up, John and Sherlock were standing in the doorway.

"Right," said Rosie. "And what do you have that made them want to go after you?"

Sherlock nodded at her and turned to John. "Good to see she doesn't have your intelligence."

"What's that supposed to mean?" John asked, affronted.

"She just woke up to a concussion and after being kidnapped, and she's already asking the right questions."

Rosie shook her head and John groaned. Mary smiled. "She's always been smarter than John."

"Hey!"

Sherlock smiled fondly at Mary before turning to Rosie. "I think you know what they were after."

Rosie pinched her lips at him and shook her head. "No."

Sherlock looked at her with an eyebrow raised and his hands in his pockets. "The young woman who figured out the puzzle box I sent you at ten, who figured out the necklace was a pin, who can beat Mycroft at chess, and who was able to unlock the stiff metal ankle cuff on her ankle knows exactly what they were after."

Rosie glanced up at her parents, both of which were frowning at Sherlock. She pointed to her book bag in the corner and John got up to get it. When he gave it to her, she pulled out an old, abused copy of Romanian myths and legends. She opened it up and wiggled her fingers for the pin on the bedside table. When her mother handed it to her, she opened the pin, slid it between the cover and the paper on the inside. Gently peeling the paper back she reached in and took out a small piece of browning paper and held it out to Sherlock.

Sherlock grinned and took it from her gently. "Clever girl." He said with a smile. She grinned back. "You left it in your violin case, you moron."

She grinned back. "You left it in your violin case, you moron."

John glanced between the two of them. "What is that?"

Sherlock looked over at Rosie and nodded. Rosie sighed. "They're numbers. Bank and routing numbers for offshore accounts that contain money and weapons plans from a Korean Defense plant that was stolen about twenty years ago."

John blinked at her and then turned to Sherlock. "You gave my daughter stolen Korean defense plans to hide? Are you out of your mind?"

Sherlock grinned. "I needed to give them to someone who no one would suspect. Anyone might consider that you or Mary might have it, or Mycroft, but no one would suspect that a sixteen-year-old girl would have them."

John breathed out his teeth in frustration. "My daughter has had sensitive information since she was sixteen? Sherlock…"

Sherlock waved the paper at her. "It was fine."

John turned back to look at Rosie. "Why didn't you tell us?"

Rosie shrugged. "He asked me not to."

"How did he do that?" Mary asked.

Sherlock grinned. "Clever, clever girl."

Rosie smiled up at her godfather. "The waltz he gave me. It took me a little while, but there were certain notes and squiggles on the pages that didn't make sense. Looked around and figured out it was the old Chinese number system that you two came across in when you solved the case with the Chinese gangsters. The book was the one he gave me when I was five. It was only a matter of decoding it."

Sherlock looked up at his friends. "You didn't think it was curious, all the puzzles and activities I'd sent her over the years."

John stared at him, before looking over at Rosie. "When did you figure it out?"

Rosie shrugged. "I suppose I've always known. You told me he was tricky. It's the basis behind all the stories I've heard over the years. There had to be a reason for the puzzles and books."

Sherlock leaned over and kissed her on the cheek. "Good girl."

Rosie smiled, and then yawned. Her father reached over and patted her knee. "Why don't you get some sleep, kiddo. I have to yell at your Uncle some more."

Rosie nestled into the pillows and nodded. "Go easy on him. He didn't really have anyone else to turn to, at least no one people would suspect."

Sherlock chuckled. "Definitely cleverer that you, John."

John growled in his chest and began ushering his friend and wife out of the room. Before they left, Rosie spoke up, "Uncle Sherlock?"

He turned to look at her, "Yes?"

"You sticking around this time? I know dad would like it."

Sherlock nodded with a smile. "I do believe it is high time I retired, don't you."

"Plenty of cases and puzzles in London." She said with a grin.

"True," Sherlock admitted with a smile.

"Lestrade still works at the police station." Rosie said, eyes closing sleepily.

Sherlock nodded, grin widening. "Sleep now, clever girl."

Rosie shut her eyes completely, falling into sleep. Tomorrow she'd need to arrange to move her studies back to London. Close to 221B Baker street if possible.

She had feeling things were about to get very interesting.


End file.
